Question: Solve for $y$ : $25 + y = -18$
Subtract $25$ from both sides: $ \begin{eqnarray} \\ 25 + y &=& -18 \\ \\ {-25} && {-25} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{25 + y} &\hphantom{=}& \hphantom{-18} \\ y &=& -18 {- 25} \\ \end{eqnarray} $ Simplify. $ y = -43$